1. Field of the Invention
The present invention relates to an image forming apparatus having a feed mechanism that feeds image formation target materials. In addition, the present invention relates to a feed mechanism that feeds image formation target materials.
2. Related Art
Conventionally, image forming apparatuses such as copy machines include a housing in which an image forming portion is disposed to be housed, and a feed mechanism (device) that feeds paper (image formation target materials) into the housing.
The feed mechanism of an image forming apparatus typically includes a feed roller that feeds paper (image formation target material) to inside of the housing, and a pad unit (separation unit) that has a separation pad member (separation member) disposed so as to oppose the feed roller and insert, therebetween and the feed roller, paper. The feed roller and pad unit of the feed mechanism are consumable items that tend to wear and deteriorate. As a result, worn or deteriorated consumable items such as the feed roller and pad unit in the feed mechanism are replaced by a user with a new feed roller or pad unit.
In this operation, a user may forget to install the new feed roller or pad unit into the feed mechanism when replacing the feed roller or pad unit. In a case of the feed mechanism being operated in a state in which the user has forgotten to install the new feed roller or pad unit, a malfunction will occur such as a paper jam in the feed mechanism.
To address this, an image forming apparatus has been proposed that includes a feed roller detection means, for example, as a technology to suppress forgetting to install a new feed roller in the feed mechanism.
However, with such a feed mechanism, the feed roller detection means is not a means for detecting the presence of the pad unit including the separation pad member.
In addition, the pad unit including the separation pad member is covered by the feed roller in the state installed in the feed mechanism, and thus it may be difficult to determine whether it is installed or not from outside.
Furthermore, even in a state in which the unit including the separation pad member is not installed in the feed mechanism, paper may be disposed at a position that can be fed by the feed roller. In such a case, there has been a problem in that a severe paper jam occurs from a plurality of sheets of paper being fed at one time when the feed roller is rotationally driven. Moreover, there has been a problem in that a failure will occur in the feed mechanism or the image forming apparatus equipped with this feed mechanism due to such a severe paper jam.